Darmstadt 2008 – wissenschaftliches Programm
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HK: Fachverband Physik der Hadronen und Kerne
HK 44: Elektromagnetische und Hadronische Sonden I
HK 44.5: Vortrag
Freitag, 14. März 2008, 15:15–15:30, 1B/C
Measurement of the depolarizing pe cross section using co-moving electrons — •Dieter Oellers for the PAX collaboration — Institut für Kernphysik, Forschungszentrum Jülich, Deutschland
In order to perform experiments with polarised antiprotons (PAX-Collaboration) one needs an effective way to produce a stored polarized antiproton beam. FILTEX showed that an unpolarised proton beam is polarised when travelling through a polarised hydrogen target. For this result there exist two competing theoretical explenations. One with a strong contribution from electrons while the other sees an almost exact cancellation of all electron effects. New calculations by Walcher and Arenhoevel suggest a very large cross section for the spin-exchange between protons and electrons of ⟨ σ Pzz⟩ ≈ 2 · 1013 barn at small relative velocities T ≈ 1.7 keV. First results of a depolarising measurement at these low energies are shown in this talk.